Trends From 2010 to 2019 in Opioid and Nonopioid Pain Management After Total Knee Arthroplasty

Introduction: As the opioid epidemic enters its third decade, we reflect on how it has affected clinical practice within the orthopaedic community. Recent studies show prolonged opioid use after total knee arthroplasty (TKA) is associated with worse overall health outcomes. This study aims to elucidate trends in pain management after TKA over the past decade. Methods: A retrospective analysis was performed using the PearlDiver database from 2010 to 2019. Patients who underwent primary TKA without a history of mental illness, complex pain syndromes, or opioids used 6 months before surgery were selected. Postoperative prescription filling rates of opioid and nonopioid at 30, 90 days, and 1 year from surgery were analyzed. Linear regression analysis and compound annual growth rates (CAGRs) were analyzed from 2010 to 2019, a P value <0.05 being considered significant. Results: Between 2010 and 2019, 579,269 patients underwent primary TKA. At 30 days, filling of prescriptions for opioids (CAGR = 3.54%) and nonopioids (CAGR = 15.50%) markedly increased from 2010 to 2019. At 90 days, opioids decreased (CAGR = −4.42%). At 1 year, opioid (CAGR = −10.92%) and nonopioid (CAGR = −2.12%) prescriptions markedly decreased from 2010 to 2019. Discussion: This study highlights patterns of decreased opioid prescription rates at 90 days and 1 year postoperatively from 2010 to 2019. Decreasing opioid rates may indicate effectiveness in targeted public health campaigns to curb opioid overuse.

policies to reduce the volume of prescribed opioids.Notably, orthopaedic surgeons are the third highest prescribers of opioids among physicians in the United States. 5To reduce the risk of opioid abuse in patients, the American Academy of Orthopaedic Surgeons implemented their revisions to pain management guidelines in 2015, which included limiting opioid prescription size, extended-release opioids, and preoperative opioid prescriptions.An analysis by Tan et al 6 found that postoperative patients, between 2014 and 2017, may consume less than half of the medication they are prescribed.A separate study found that one-third of TKA patients have preoperative opioid use within 3 months of surgery, which is a strong predicative indicator of increased opioid prescription refills. 7There is also evidence that chronic opioid use is a common occurrence after TKA surgery, especially in patients with a history of psychiatric diagnoses. 8It is also known that opioids in the home increases the risk of opioid overdose of others in the home. 9This study's aim was to identify trends in opioid prescription filling for patients after TKA.We hypothesized that opioid prescription volume would decrease over the study period.

Methods
A retrospective trends analysis was conducted using the PearlDiver (Mariner data set) database (www.pearldiverinc.com;10435 Marble Creek Circle).The Mariner data set contains over 120 million patients and includes all payer claims information from 2010 to 2020.This includes cash pay, private insurance, Medicare, Medicaid, and any other payment form.The PearlDiver database includes records from the United States without geographic limitation and includes all claims regardless of provider type.Patient records were selected using the International Classification of Disease (ICD), Common Procedural Terminology, Uniform System of Classification, and codes specific to PearlDiver.Codes used are provided in Supplemental Appendix (http://links.lww.com/JG9/A343) for reference.This study was institutional review board exempt because the database only permits the extraction of deidentified patient information.

Selection Criteria
Patients were selected using Common Procedural Terminology, ICD-9, and ICD-10 codes who underwent primary TKA between 2010 and 2019 met initial inclusion criteria.][12][13] Follow-up periods of 30 days, 90 days, and 1 year after TKA were chosen to elicit short-term and long-term use of medications.Medications were broken into two categories: (1) opioids and (2) nonopioids.Nonopioids consisted of nonsteroidal anti-inflammatory medications (celecoxib, diclofenac, ibuprofen, ketorolac, meloxicam, and naproxen) and gabapentinoids (gabapentin and pregabalin) with their associated brand names as well.Of note, these claims represent prescriptions filled, including refills, and do not include the total number of prescriptions written or consumption of medications and will be referred to as prescriptions.

Analysis
Annual prescription prevalence rates (patient records with prescription/total patient records included) were calculated for opioids and nonopioids at 1 to 30 days (30 days), 31 to 90 days (90 days), and 91 to 365 days (1 year).These were calculated for each year (2010 to 2019).Average daily milligram morphine equivalents (MME) were also calculated for the filled prescriptions within the 30-and 90-day periods.Linear regression and CAGR ((Y2/Y1) 1/(Y2 2 Y1) 2 1; Y1 = first year of the analysis, Y2 = final year) were calculated to analyze trends in prescriptions from 2010 to 2015, 2016 to 2019, and 2010 to 2019.The year 2016 was used as a proxy for the implementation of new guidelines.A P value of ,0.05 was considered significant.PearlDiver does not report patient records with less than 11 claims to protect privacy.

Results
In total, 579,269 patients underwent TKA between 2010 and 2019 and met our inclusion criteria.Of these, 412,554 patients had follow-up for 30 days, 379,054 patients had follow-up for 90 days, and 79,879 patients had follow-up for 1 year (Figure 1).
Trends in the average daily MME significantly decreased between all time points: 2010 to 2015 (P =

Figure 1
Flowchart of selection of the study population with appropriate follow-up within the PearlDiver database.

Discussion
Using a national claims database, this study found varying trends in postoperative TKA opioid utilization from 2010 to 2019.The PearlDiver insurance database allowed for selection of anonymized patient data based on history of psychiatric diagnoses, prescription medication history, and mental health history (Figure 1),

Figure 2
Graph showing annual rates of filled prescriptions for opioids and nonopioids within 30 days of TKA from 2010 to 2019.TKA = total knee arthroplasty

Figure 3
Graph showing annual rates of filled prescriptions for opioids and nonopioids within 90 days of TKA from 2010 to 2019.TKA = total knee arthroplasty

Research Article
Tyler Bahoravitch, MD, et al average opioid prescriptions decreased leading up to 2016 before leveling out; a similar pattern was observed in nonopioid prescriptions.The linear regression of MME at 30 days postoperatively annually was 0.35% less than that of the linear regression of MME at 90 days postoperatively annually, indicating the reduction in opioids was relatively consistent from 30 to 90 days postoperatively.This is possibly explained by stable pain trajectories after TKA were seen in the same 30-and 90-day periods in an analysis by Dumenci et al, 14 particularly in patients with poor surgical outcomes.
At 30 days postoperatively, the rate of opioid prescriptions increased until 2015 and then plateaued while nonopioid prescriptions continued to increase.This timing demonstrates that the change in American Academy of Orthopaedic Surgeons protocol may have affected physician prescribing behaviors.Two studies by Reid et al analyzed data from 2016 to 2017 on the impact of state-level legislation in Rhode Island on limiting opioid distribution after orthopaedic procedures and found notable year-over-year reduction in initial and 30-day postoperative opioid prescriptions after such laws went into place after spine surgery and a .50%decrease in the number of opioid pills prescribed after six common orthopaedic procedures. 15,16This varies from our findings that show a plateau in opioid prescriptions was reduced after 2016 rather than a yearover-year decrease in rates of opioid prescriptions.One likely explanation for the discrepant data could be because of the small population of Rhode Island, and its effect was negligible given this study's nationwide database used.Regardless, legislation alike also played a role in opioid prescriptions over the study period.
When examining opioid prescriptions at 90 days (Table 3), no clear trend was observed through 2015; however, prescriptions starting in 2016 decreased precipitously in what ended up being a change from 46.15% of patients filling prescriptions at 90 days postoperatively to 30.71%.Conversely, nonopioid prescriptions increased steadily from 2010 to 2016 and then plateaued (Figure 3).This divergence means that a certain number of patients were no longer filling prescriptions for any pain medications-opioid or nonopioid.This finding is noteworthy because it may signify overprescribing of opioids after TKA, which is supported by a study by Etcheson et al 17 who found no association between total opioid consumption after TKA and factors like patient's pain management satisfaction or overall hospital rating.
At 1 year postoperative opioid prescriptions decreased before 2016 and then flattened.For this period, both nonopioid and opioid prescription claims leveled out after 2016.Approximately 3% of TKA patients who were prescribed opioids continued to refill their prescription at and beyond 1 year.This differs from findings in a study by Cook et al, 18 where 13% of TKA patients with no history of opioid use 6 months before surgery continued to fill prescriptions 1 year after surgery.Of course, there are other factors that influence postoperative pain for which data were not examined in our retrospective study.Among these factors is surgical time, where longer tourniquet time has previously been correlated with persistent opioid use after TKA. 19Other factors include sex, age (at the time of surgery), mental health history, and preoperative opioid use. 20here are many variables that affect patient experience and outcome, and guidelines and regulations were not implemented in a vacuum.With the increased profile of opioids addictive chemistry, perioperative anesthesia techniques (regional and spinal anesthesia) and  21 This study contributes evidence toward a movement promoting multimodal pain management as the standard of care, in turn reducing dependence on opioids.This examination of insurance claims data relies on provider coding and proper billing habits of institutions.The database cannot be used to determine from which

Research Article
Tyler Bahoravitch, MD, et al provider the prescriptions originated from.While prescriptions filled less than 30 days after TKA were more likely to be prescribed by an orthopaedic provider, this could not be ascertained from PearlDiver.Another limitation is that many nonopioids can be bought over the counter and could not be assessed because only prescribed medications would show up in the PearlDiver database.Pain was also not able to be assessed in this analysis.Regardless, the data provided helps assess prescription practices after TKA.While the data presented here does not include dose, drug, prescription length, or consumption of opioids by patients, it does highlight the decreasing volume of circulating opioids after TKA.

Conclusion
This study's analysis found a trend of reduced MME filled after TKA within 30 and 90 days postoperatively.Current trends of opioid prescriptions filled are stable at 30 days and decreasing at 90 days and 1 year.Nonopioids are also being increasingly used within 30 days of TKA while chronic use of both opioids and nonopioids after TKA are reducing greatly.While these findings are impactful to the opioid epidemic, there are limitations to what these patterns can be attributed to.Factors such as societal or governmental guidelines, physician awareness about the opioid epidemic and the resulting changes in prescribing behavior, and local legislation on prescribing opioids influence prescriptions over the period studied.Additional analysis, while accounting for these factors, is needed to determine which methods had the greatest effect on combating the opioid epidemic.

Table 2 .
Daily Average Milligram MorphineEquivalents and Trends From 2010 to 2019 of Filled Prescriptions Within 30 Days After Total Knee Arthroplasty MME = milligram morphine equivalentP values ,0.05 bolded for significance and correlating compound annual growth rates (CAGRs).

Table 3 .
Annual Prevalence (2010 to 2019) and Trends of Filled Opioid and Nonopioid Prescriptions Within 90 Days P values ,0.05 bolded for significance and correlating compound annual growth rates (CAGRs).

Table 4 .
Daily Average Milligram Morphine Equivalents and Trends From 2010 to 2019 of Filled Prescriptions Within 90 Days After Total Knee Arthroplasty

Table 5 .
Annual Prevalence (2010 to 2019) and Trends of Filled Opioid and Nonopioid Prescriptions Within 1 Year P values ,0.05 bolded for significance and correlating compound annual growth rates (CAGRs).